Just over a month ago, I found a good site for learning Japanese. Caveat: It's paid, and though cheap per month, it only bills per year, so I had to put down >$80 once the trial ended.
However, I don't regret it at all. The lessons are clear and informative, and the program's flashcards are integrated seamlessly with them. Most important for me, there's a daily streak system, which is very helpful in making sure that I do at least a bare minimum each day.
You can choose anything from a one-year to a four-year pace to complete their program, which will supposedly place you at JLPT N1, i.e. functionally equal to a native. From what I've seen so far, that seems plausible. At the very least, I'm sure that I've learned more in 30 days than I would in a semester-long university course. At an average of 2.5 lessons per day (the fastest pace being 4), I've covered 375 kanji and just under 500 vocabulary items. It takes about 1-2 hours per day, depending on whether or not I do the full 4 lessons. If I was taking the most casual pace with 1 lesson per day, it would probably take no more than 30 minutes (and by this point, I would be at ~160 kanji/200 vocab words).
Highly recommended if you have any interest in learning Japanese, especially if you're a lazy fuck and have trouble learning languages because of it: https://www.nativshark.com/my-journey